Yoshimura Performance Products Review

We slap a full RS-5 exhaust, PIM II and DATA Box on our LT-R450

Story by Jeff M Vanasdal, Photography by Landon Glass, Dec. 02, 2009

For past couple of months we’ve had a 2009 Suzuki QuadRacer LT-R450 in our garage and we were looking for a way to add some additional horsepower without opening up the engine cases. Because of its very successful relationship with Suzuki ATV racing, we called up Yoshimura R & D to see what was available in the way of bolt-on power.

For more than 50 years Yoshimura has been developing some of the most powerful performance modifications for motorcycles and ATVs on the planet. It so happened that Yoshimura just released its new PIM II mapping unit and wanted us to test it out. In addition to the PIM II, Yoshimura also sent along a few other top selling products. For the everyday rider on a budget or a serious racer, Yoshimura has a product that can help you get the most out of your ATV.

We first started by applying Yoshimura’s popular Cherry Bomb. This is by far the cheapest and easiest way to add bolt on (or in this case plug in) power to the LT-R450. At a very reasonable price of $39.95 you can add horsepower in minutes! Installation was quick and easy as you simply plug the unit in and you are ready to hit the track. It’s pretty incredible how much power this little unit can add. The Cherry Bomb can be run with the stock exhaust or with an aftermarket exhaust. After playing around for a while with the Cherry Bomb and the stock exhaust, we decided to add a Yoshimura exhaust to the mix.

Yoshimura supplied a RS-5 exhaust for our project. The Yoshimura RS-5 was built with power and strength in mind. The header and mid pipe is made of durable stainless steel while the muffler sleeve was constructed from high-grade aluminum. Yoshimura also offers a titanium muffler sleeve to further cut down on the weight when shaving those extra pounds is a must.

The RS-5 has a deep throaty sound to it that comes alive every time you crack open the throttle. A 96 db USFS approved low volume insert in included to keep those park rangers and track officials off your back. The RS-5 exhaust can be purchased as just a slip-on ($435.00) or you can order the full system ($595.00) that includes the slip-on, mid pipe and header. The RS-5 delivers a more snappy response out of the hole and allows for a wider array of power throughout the midrange and top end.

An additional hop-up we did to our LTR450 was adding a new fuel mapping system. Yoshimura’s new PIM II ($339.95) features a full range of mapping that can be tuned in very fine increments. The system can be tuned from the lowest 500 rpm and at 10 % throttle intervals. The PIM II also features 400 adjustment points in +/- 1% increments. This mapping system is very easy to install because Yoshimura includes a complete plug-in-play wiring harness with every order.

The system comes preloaded with two separate maps. One is set up to be run alongside the Yoshimura RS-5 exhaust slip-on and the other it set up for the full system. If the preset maps aren’t enough, you can always visit Yoshimura’s website to download additional maps for free!

The PIM II comes with software that you can install on your own computer. Unlike the old day of messing with the carb with this system you can access your LTR’s life source and make very fine adjustments quickly and easily. No matter what engine modifications you’ve made or what brand exhaust you are using, Yoshimura has a map that will match your setup.

If you feel you need to fine-tune your mapping as we did, Yoshimura also offers the DATA Box ($429.00). The DATA Box is designed to take the confusion out of custom mapping. The DATA Box features a self-mapping system that automatically calculates the required fuel adjustment at each RPM and throttle position to reach the riders target air fuel ratio. All this is done while the rider is aboard the machine.

The DATA Box is a different option to custom mapping and is designed to cut down the cost and time of using a custom dyno. Although the system was designed to be used by the consumer, if you want to harness all the potential power from your LTR and don’t feel comfortable with creating your own mapping we would suggest taking your LTR to a local dyno and having a professional help you tune your ride alongside the DATA Box.

With its long history of performance and high quality products, its no surprise Yoshimura powers some of the top riders to the finish line every weekend around the world. If you want to get more power out of your LTR, Yoshimura has just the product you need to get you across the finish line first or beat your friends down the trail.

Note: Stay tuned for details as ATV.com will be giving away all these Yoshimura products in the New Year. We’ll post details on ATV.com, as well as our sister forum - LTR450 Central.